/**
 * @file
 * SNMP netconn frontend.
 */

/*
 * Copyright (c) 2001-2004 Swedish Institute of Computer Science.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 * 1. Redistributions of source code must retain the above copyright notice,
 *    this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright notice,
 *    this list of conditions and the following disclaimer in the documentation
 *    and/or other materials provided with the distribution.
 * 3. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT
 * SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING
 * IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY
 * OF SUCH DAMAGE.
 *
 * Author: Dirk Ziegelmeier <dziegel@gmx.de>
 */

#include "lwip/apps/snmp_opts.h"

#if LWIP_SNMP && SNMP_USE_NETCONN

#include <string.h>
#include "lwip/api.h"
#include "lwip/ip.h"
#include "lwip/udp.h"
#include "snmp_msg.h"
#include "lwip/sys.h"

/** SNMP netconn API worker thread */
static void
snmp_netconn_thread(void *arg)
{
    struct netconn *conn;
    struct netbuf *buf;
    err_t err;
    LWIP_UNUSED_ARG(arg);

    /* Bind to SNMP port with default IP address */
#if LWIP_IPV6
    conn = netconn_new(NETCONN_UDP_IPV6);
    netconn_bind(conn, IP6_ADDR_ANY, SNMP_IN_PORT);
#else /* LWIP_IPV6 */
    conn = netconn_new(NETCONN_UDP);
    netconn_bind(conn, IP4_ADDR_ANY, SNMP_IN_PORT);
#endif /* LWIP_IPV6 */
    LWIP_ERROR("snmp_netconn: invalid conn", (conn != NULL), return;);

    snmp_traps_handle = conn;

    do
    {
        err = netconn_recv(conn, &buf);

        if (err == ERR_OK)
        {
            snmp_receive(conn, buf->p, &buf->addr, buf->port);
        }

        if (buf != NULL)
        {
            netbuf_delete(buf);
        }
    }
    while(1);
}

err_t
snmp_sendto(void *handle, struct pbuf *p, const ip_addr_t *dst, u16_t port)
{
    err_t result;
    struct netbuf buf;

    memset(&buf, 0, sizeof(buf));
    buf.p = p;
    result = netconn_sendto((struct netconn *)handle, &buf, dst, port);

    return result;
}

u8_t
snmp_get_local_ip_for_dst(void *handle, const ip_addr_t *dst, ip_addr_t *result)
{
    struct netconn *conn = (struct netconn *)handle;
    struct netif *dst_if;
    const ip_addr_t *dst_ip;

    LWIP_UNUSED_ARG(conn); /* unused in case of IPV4 only configuration */

    ip_route_get_local_ip(&conn->pcb.udp->local_ip, dst, dst_if, dst_ip);

    if ((dst_if != NULL) && (dst_ip != NULL))
    {
        ip_addr_copy(*result, *dst_ip);
        return 1;
    }
    else
    {
        return 0;
    }
}

/**
 * Starts SNMP Agent.
 */
void
snmp_init(void)
{
    sys_thread_new("snmp_netconn", snmp_netconn_thread, NULL, SNMP_STACK_SIZE, SNMP_THREAD_PRIO);
}

#endif /* LWIP_SNMP && SNMP_USE_NETCONN */
